In the sewage disposal art, drainfields are used to distribute liquid effluent into the soil for percolation into the ground. Typically, a collection tank collects the raw sewage, and a primary settling of solids occurs in that tank. A liquid line receives liquid effluent from the settling tank and conveys the fluid either by gravity or by pumping to a distribution tank. The liquid in the distribution tank then flows from the tank through a series of lines into the drainfield, where the liquid percolates into the ground.
The distribution tank is typically a large concrete tank, and a plurality of openings are formed in a sidewall of the tank for connection to the drainfield lines. For the most efficient use of the drainfield, it is important that the liquid be distributed even into the multiple discharge lines exiting the distribution box. Only with even distribution of the liquid are the drainfield lines evenly used. For example, if the openings out of the distribution box are not precisely level, then the lowermost line will receive more liquid effluent than the higher line. This will result in uneven absorption in the drainfield, and can cause premature failure of the drainfield.
However, the quality of the installation of the drainfield lines is largely a matter of the skill of the installer. Because the distribution box is a large concrete tank, it is quite heavy and not easily moved. For this reason, the outlet holes are generally drilled or chiseled into the wall of the box after the box is installed in the ground. The liquid flows into the distribution box until it reaches the level of the outlets, and then flows outwardly through the outlets into the absorption lines in the drainfield. After these holes are made in the wall of the box, the drain lines are connected to the outlet holes.
The prior art has attempted to deal with the problem of creating an even discharge flow through a number of different techniques. For example, U.S. Pat. No. 4,756,827 discloses a metering device which comprises an end cap for the distribution lines with a circular opening formed in the end cap offset from the center of the cap. By rotating the cap, the height of the opening may be precisely adjusted.
Another solution is proposed in U.S. Pat. No. 5,098,568, which provides a fixed flow divider in order to apportion the effluent discharge.
Still another solution to the problem is provided in U.S. Pat. No. 4,614,584 which incorporates a screening device and a flow control to equally apportion the discharge.
Unfortunately, while prior attempts to solve the problems with distribution boxes have had varying degrees of success, they still have not fully solved the problems in an economical fashion, and each has drawbacks.
Accordingly the primary object of the present invention is to provide an improved liquid distribution device for use with sewage disposal drainfields.
Another object of this invention is to provide a liquid distribution device which may be easily installed.
Yet a further object of this invention is to provide a liquid distribution device which includes a metering opening for each of the distribution lines.
Still another object of this invention is to provide a liquid distribution device which may be easily levelled in order to provide accurately distributed fluid flow to the drainfield.
Yet another object of this invention is to provide a liquid distribution device which is inexpensive and easy to manufacture.